H-Shield HD is a 1 ⁄2" thick high-density polyiso insulation panel specifically designed for use as a cover board. It is manufactured on-line to a premium performance coated glass facer on both sides (CGF). H-Shield HD delivers an R-value of 2.5 in its 1 ⁄2" profile; significantly higher than roof cover boards made with other materials such as wood fiber or gypsum.